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$ Gas Saving Tips $

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What Really Saves Gas
Gas saving tips tested -- with amazing results.

*** By Editors ***

Gas-saving tips have an urban legend appeal.

Someone at a party might say, "Hey, did you know that if you drive with your windows up and the air conditioning on, it actually saves gas? It's more aerodynamic."

"Huh," you say, "I didn't know that. That's interesting."

Interesting, yes. True? Well, maybe not.

We took the top four fuel economy tips and put them to a real-world test. Our goal was simple: to see what tips produced a measurable difference in fuel economy. We say "measurable" (meaning detectable by an ordinary driver, not a lab technician) because most people want to see an improvement in their fuel economy that saves dollars, not just pennies.

Fuel economy tips seem to get passed on from person to person until they lose their source and their validity. This was our chance to reverse the trend.

The Tests
We chose four fuel economy tips and took two cars from the long-term fleet, and drove eight 56-mile loops. Our route circled Owens Lake near Lone Pine, California, at the foot of Mount Whitney, the tallest mountain in the lower 48 states. We chose the route because it was so deserted we could vary our speed and driving style without interfering with the flow of traffic. The only other cars we saw on the route were a group of testers from Mercedes-Benz, trying out a heavily cladded prototype.

The Vehicles
We drove the long-term 2005 Ford Mustang GT and the 2005 Land Rover LR3 SE. The Mustang, with a manual transmission, is a sleek coupe; the Land Rover, with an automatic, is a boxy SUV. Both vehicles have V8 engines. The Land Rover is rated at 14 mpg city and 18 mpg on the highway according to the EPA estimates posted on The Mustang's EPA estimated mileage is 15 mpg city and 25 on the highway.

In earlier studies, we have found that the EPA estimates do not reflect the mileage that most drivers will actually record. In "Real World vs. EPA Estimates", we found that most drivers will actually get less than the city mileage.

Testing Method
The Land Rover has an onboard computer to calculate several driving factors including gas mileage, distance traveled and average speed. We felt the results in the Land Rover were extremely accurate. After each loop we refueled the Mustang at the same filling station and at the fuel pump to see how gas mileage varied.

Since the tests were to compare the difference between variables, we knew that we had to standardize them as much as possible. Consequently, we always drove the loops back-to-back to minimize differences in the temperature and wind direction. The two cars were driven in tandem separated by about a tenth of a mile. Results were measured and computed immediately after the loops were driven.

Test #1: Effect of Using Cruise Control

Result: Big-time savings!
Here's a bit of advice that surfaces frequently on tips lists. Usually, the recommendation is to use cruise control "selectively." This means not to use it in the mountains since it will try to keep the car up to speed no matter what grade you are climbing. We have always agreed with this tip in theory but we hadn't expected such significant results. As soon as we began driving the loop we realized it would be important. First, it smoothes out the driver's accelerator input by keeping nervous drivers from "surging." Second, it forces the driver to take the long view of the road instead of reacting to every change in the traffic.

Method: We drove the two test cars 56.8 miles once with the cruise control on and once by controlling the car manually. With the cruise control on we set it at 70 mph. With the cruise control off we varied our speed between 65 mph and 75 mph. We tried to mimic the driving style of a person who is in moderate freeway traffic.

Land Rover
With cruise control 19.6 mpg
Without cruise control 17.2 mpg

Percent change 13.9 percent improvement

With cruise control 23.3 mpg
Without cruise control 22.3 mpg

Percent change 4.5 percent improvement

Test #2: Effect of A/C On, Windows Up vs. A/C Off, Windows Down

Result: Mixed
This has got to take you back to the days with the family on vacation. Dad says, "Turn the A/C off! It wastes gas!" And Mom says, "We can't roll the windows down or everyone on the highway will think we can't afford A/C." And you're in the back roasting, hoping someone will win the argument so you can cool off.

Well, family psychology aside, Dad wasn't necessarily right. While the A/C compressor does pull power from the engine wasting some gas, the effect appears to be fairly minimal in modern cars. And putting the windows down tends to increase drag on most cars, canceling out any measurable gain from turning the A/C off. But this one depends on the model you're driving. Still, in our experience, it's not worth the argument because you won't save a lot of gas either way. So just do what's comfortable.

Method: We drove the same loops at equal speeds both times, 65 mph. The first loop we drove with the A/C on and the windows up. The second loop we drove with the A/C off and windows down.

Land Rover
With A/C on, windows up 19.3 mpg
With A/C off, windows down 19.6 mpg

Percent change 1.6 percent improvement

With A/C on, windows up 29.5 mpg
With A/C off, windows down 30.7 mpg

Percent change 4.1 percent improvement

Test #3: Lead-Foot Driving vs. Feather-Foot Driving

Result: Major savings potential.
This is gonna hurt. From all our testing, the most successful method for saving gas is: you. And we're talking massive fuel economy gains. Think you need a hybrid? Well, chances are you've got hybrid-style mileage improvements already in your gas pedal foot. Don't mash the gas pedal when you stop and start. Take the long view of the road and brake easy. This tip alone can save you unbelievable amounts of gas. We found that if you slowed your 0-to-60 time down to 20 seconds from a normal city driving pace of 10 to 15 seconds, you'll feel the savings immediately.

Method: We drove the same loops as before, once by accelerating aggressively 15 times at three-fourths throttle from zero to a cruising speed of 75 mph. We also applied the brakes hard as if coming to a stoplight. In the second loop we accelerated moderately 15 times at one-fourth throttle to a cruising speed of 70 mph. We braked lightly to a full stop.

Land Rover
With lead foot 14.1 mpg
With feather foot 19.1 mpg

Percent change 35.4 percent improvement

With lead foot 18.1 mpg
With feather foot 23 mpg

Percent change 27.1 percent improvement

Test #4: Low Tire Pressure vs. Properly Inflated Tires

Result: Important for many reasons
No matter how many times drivers hear that tire pressure is important they hate checking it. Probably because they don't like squatting beside their car in a busy gas station with fumes swirling around them. But it is important, for a number of reasons. Properly inflated tires are less likely to fail at high speeds. They wear more evenly and, yes, they deliver better gas mileage. How much? In this test we saw a modest but noticeable difference. It might have been more dramatic if the test was conducted at a lower temperature; it was 108 degrees Fahrenheit the day we did our tests.

Method: We drove two loops at about 60 mph. Once, the tires were 5 psi below the pressure recommended by the manufacturer. The second time, the tires were about 2 psi above the recommended around. We overinflated the tires because it's difficult to get a reliable inflation level when the tires are already warmed up. We felt that it was important to make sure the tires were inflated to the recommended level or slightly above. Furthermore, tires are constructed to allow for a certain amount of overinflation, though they will then deliver a harsher ride.

Land Rover
Underinflated tires 20.5 mpg
Properly inflated tires 21.4 mpg

Percent change 4.4 percent improvement

Underinflated tires 23.7 mpg
Properly inflated tires 23.7 mpg

Percent change 0 percent improvement *

* We felt that because of the high temperatures the tires were never sufficiently underinflated enough to show a difference. Even though we deflated them by 5 psi when cold, the high temperature brought them back up to the required inflation level.

The good news is that you can drastically improve your gas mileage. The caveat is that you have to change your driving habits. Basically, stop driving like a maniac and use that cruise control. Who knows? You might like the new you.

On other fronts, be sure to check your tire inflation both to save gas but also to be safe and promote even tire wear. And regarding that air conditioner, well, if you want to drive around with your arm hanging out of the window it won't really change your gas mileage much.

Now, when someone sidles up to you at a party and says, "You know, washing your car will improve the gas mileage,'" you can lock eyes with them and say, "I heard that, too. Turns out the difference is so small it's insignificant."
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Great info, Thanks for the pot and effort.
It is interesting that they found it more efficient to drive at freeway speeds with the A/C off and windows down. I guess you never know untill you test it out. :rolleyes:
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As we all know the Armada's don't get the greatest gas mileage. You all seem to be pretty knowledgeable about these vehicles and wanted to see if any of you have any affordable tips you could share. I have installed a K&N drop in filter but haven't seen a much of a gain. Wanting to do the muffler swap, did that help any? Any other suggestions?
Welcome to the Club!! The Mada's are gas guzzlers and it really doesn't matter what you do they will never be economical. Better breathing(intake and exhaust) will help, but then you'll have the tendency to put the "pedal to the metal", and that will hurt MPG. Drive gently (really hard for me!!) and you'll save a few drops.
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Thanks for the welcome. I forgot has anyone swapped the spark plugs for a hotter spark such as E3 plugs?
not yet but i can tell you that on long drives i got 18mpg
i found that after riding in buddies Hemi Cherokee on the streets i love the mileage i get
Nitrogen filled tires at OEM pressure or a few pounds over.
OEM size tires
OEM tread pattern tires
Synthetic oil
Inspect and change (when needed) the air filter.
Don't go over the speed limit.
Big Tow package gets less MPG than non-tow versions.
Smooth acceleration, look ahead and plan for braking
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Thanks for the welcome. I forgot has anyone swapped the spark plugs for a hotter spark such as E3 plugs?
Save your money. The E3 plugs, Splitfires, Pulstars... all hype. They won't do anything except make your wallet lighter than usual, lol. Stick with the NGK platinums or iridiums and if those aren't readily available, the Denso counterpart(s) are just as good.

The Mada's are gas guzzlers and it really doesn't matter what you do they will never be economical
^^^ That says it all right there. I doubt anyone here on this forum even considered the MPG when buying the armada. The way I see it, once you leave the sedan body class, you can forget about MPG in most cases.
Bone stock 08 SE running full syn oil. 17 - 18 mpg for me on the hwy @67mph indicated (smack dab between 65 & 70) really only going 65 as indicated by gps nav. and pacing my wife in her car. Speedo is off by
2 1/2mph (but that is another thread). I drive with the cc engaged as much as possible when on highway, in the city its just a dog, expect 12 - 14 mpg. Keep your tire pressure up!
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WOW you do 67mph? i bow down to you sir!
With my travels between the Baltimore area and Ohio, I can't seem to go less than 80!! I bow to you as well!!:bow::bow:
I like being able to get upwards of 18 mpg in that thing, most wouldn't expect it to be able to. I've just made up my mind that thats what I'm going to do.:D
Well I just did a test. Mixed city and freeway driving (including a trip between Austin and San Antonio Texas) and came out with about 16.2mpg. I drove 342 miles on 21 gallons (filled up with 1/4 tank left). Freeway speed was about 75mph. Not bad, not great. But considering my unaltered '02 Pathfinder 4x4 SE used to average about 15 mpg on similar driving I'm happy.

As others have stated - didn't buy it for the mileage. This is in an '08 4x2 LE Flex. Only modification was a K&N drop in filter. I have my tires inflated (cold) to 35psi. Other than that I try to pay attention to the road and figure out the "clearest" route to destination. I don't know how often you can get the listed 18 mpg - it's probably a little easier here in TX where the majority of the roads are flat (as in no mountains). I have already made a trip to Dallas from Austin and made it up, drove for 3 days and back to Waco before refueling - almost 400 miles on 7/8 of a tank but I didn't do the math at that point. I have a similar trip soon and will see what I get.
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i've found a sweet spot at 2000rpms. I always set the cc when its at 2k rpms which is about 72-73. I've gotten 18.5-18.7 on long highway drives. The thing that helped the most imo was the 2* timing advance.

I have a stock '06 SE 2WD with the Big Tow package. We drove it on a 1300 mi round trip last week to Niagara Falls from Cincinnati. Up through Detroit and Canada and back through NY, PA and Ohio. The total trip was around 1250 miles. The truck was loaded up with the family and all of our stuff. We drove around 70-72 with the A/C on for the whole trip. Including our driving around at the attractions in Detroit, and two days in Niagara Falls all running around town, we got 16.3 mpg. I just drove earlier this week on a 600 mile round trip to Michigan (all freeway) and averaged 17.3 mpg.

I am running synthetic oil, a new air filter, new Trans fluid (doubt that helps mileage) and new Mobil 1 75W-140 in the diff. Tire pressure is 35 psi. I typically let it shift at around 2K rpm and drive it very easy. My best tank on this last trip was 17.8 mpg, which was driving < 70 mph.

Overall, when we consider that our Chrysler Pacifica never got over 21 mpg, wouldn't tow over 3500 lbs and had much less room, I don't have a problem with the mileage. Who would guess that a 2WD Pacifica weighs 4500 lbs?
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My average speed is 75 so my gas mileage is shoot not to mention my points on my license.
Before the Mada i had a Mercedes ML 430 and i got 17mpg now i get 18 mpg and i have more room and towing power
I think the best gas saving tip is taking public trasnportation or stare at your monster until it rust. The problem is that I think nobody in this thread will do that. Right?
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